Moisturizing with the puspose to close crack

[Henning]

Moisturize to close crack

Hello, I have an ukulele with a crack that I hope to close. It is a 1940s or 50s mahogany.
Whenever I´ve read about this the writer says, "go very carefully ahead".
I suppose that means don´t (never ever!) over moisturize but rather let it take the time.

Now if, I can get the cracks to close, at perhaps 50% humidity, the risk of introducing tensions in the back that will cause new cracks is there, isn´t it?

Thankful for any point of view.

 

[John Colter]

If the gap has stabilized like that, in "normal" conditions of temperature and humidity, I would agree that attempts to close the gap, using artificially high humidity, run the risk (a very high risk) of further shrinkage and cracking, after the repair has been made.

I think that must be the longest sentence I have ever written - sorry!

I have used humidification to close smaller gaps very successfully. That was in a uke, only about twelve months old, that had been kept in a warm and very dry atmosphere.

I look forward to hearing what others with more experience have to say.

John Colter

 

[Henning]

I have to guess slightly, don´t think the conditions were "normal" because the instrument is still dried out considering the relatively sharp fret ends. The cracks however, assumably have been there for quite some time.

 

[John Colter]

I would be very wary of using high levels of humidity in an attempt to close those gaps. I would keep the uke for a week or so in a room with known high-ish humidity, and see if that has a beneficial effect.

If that doesn't work, I would start looking for a plan 'B'. My preferred alternative would probably be to fit a number of internal cleats, then fill the cracks.

John Colter

 

[printer2]

High levels of humidity to close a crack will do little harm, if you see the crack closed it will be obvious when to stop.